PNB 2XB3 Lecture Notes - Lecture 5: Vitreous Body, Aqueous Humour, Refractive Error

• School: McMaster University
• Department: Psychology, Neuroscience & Behaviour
• Course: PNB 2XB3
• Professor: Daniel Goldreich

Document Summary

Homework assignment #4 answers (150-50x)(2)<150-50(3-x) x>2, 2(2)= 4mm (60-20x)(2)<60-20(3-x) Myopia- (nearsighted) the focal point is in front of the retina, because the eyeball is too long or the cornea is too curved. Hyperopia-(farsighted) the focal plane is behind the retina, because the eyeball is too short or the cornea is insufficiently curved. The more curved the lens, the more the light bends. Normal line- perpendicular to interface (light coming in) In the eye, both the cornea and the lens bend light. The cornea has a fixed shape; the lens is adjustable. Bends twice- one when it enters lens and once when it leaves. If something is closer, your lens becomes rounder so you increase the angles where light enters and leaves, and it bends more to hit the retina. The cornea has greater focusing power than the lend. This is because air-> cornea (1. 38) and water-> to lens (1. 07) This is because of the ratio of refractive index of materials.